Emergency Medicine: Heart Attack and CPR

Introduction

A blood clot is the most common cause of a blocked coronary artery. Usually, the artery is already partially narrowed by atheromas. An atheroma may rupture or tear, narrowing the artery further and making blockage by a clot more likely.

The ruptured atheroma not only reduces the flow of blood through an artery but also releases substances that make platelets stickier, further encouraging clots to form.

Uncommonly, a heart attack results when a clot forms in the heart itself, breaks away, and lodges in a coronary artery. Another uncommon cause is a spasm of a coronary artery that stops blood flow. Spasms may be caused by drugs. Sometimes the cause is unknown.

About one third of people who have a heart attack do not have chest pain. Such people are more likely to be women, people who are not white, those who are older than 75, those who have heart failure or diabetes, or those who have had a stroke.

Other symptoms include a feeling of faintness, sudden heavy sweating, nausea, shortness of breath, and a heavy pounding of the heart.

Abnormal heart rhythms (arrhythmias) occur in more than 90% of people who have had a heart attack. Immediately and up to a few days after a heart attack, abnormal heart rhythms are a common reason that the heart cannot pump adequately.

Abnormal heart rhythms originating in the ventricles (ventricular arrhythmias) may greatly interfere with the heart’s pumping ability or may cause the heart to stop pumping effectively (cardiac arrest). A loss of consciousness or death can result. Sometimes loss of consciousness is the first symptom of a heart attack.

If you suspect a heart attack, seek emergency medical treatment immediately. Should a heart attack occur, you should go to the emergency room and seek help immediately. Time is of essence. Only examination by a doctor, who will administer an electrocardiogram (EKG) and/or a blood test, can confirm if you are having a heart attack.

The most important thing to do if you think you are having heart attack symptoms:

Dial 911 to call an ambulance or get to a hospital emergency room as quickly as possible so the doctor can examine and treat you.

Crush or chew a full-strength aspirin (swallow with a glass of water) to prevent further blood clotting.

Cardiopulmonary Resuscitation (CPR)

Cardiopulmonary Resuscitation (CPR) is a combination of rescue breathing and chest compressions delivered to victims thought to be in cardiac arrest. When cardiac arrest occurs, the heart stops pumping blood. CPR can support a small amount of blood flow to the heart and brain to “buy time” until normal heart function is restored.

To learn CPR properly, take an accredited first-aid training course, including CPR and how to use an automatic external defibrillator (AED).

Before you begin, assess the situation before starting CPR:

Is the person conscious or unconscious?

If the person appears unconscious, tap or shake his or her shoulder and ask loudly, “Are you OK?”

If the person doesn’t respond and two people are available, one should call 911 or the local emergency number and one should begin CPR.

If you are alone and have immediate access to a telephone, call 911 before beginning CPR — unless you think the person has become unresponsive because of suffocation (such as from drowning). In this special case, begin CPR for one minute and then call 911.

If an AED is immediately available, deliver one shock if advised by the device, then begin CPR.

Put the person on his or her back on a firm surface. Kneel next to the person’s neck and shoulders. Open the person’s airway using the head-tilt, chin-lift maneuver. Put your palm on the person’s forehead and gently tilt the head back. Then with the other hand, gently lift the chin forward to open the airway.

Check for normal breathing, taking no more than five or 10 seconds: Look for chest motion, listen for breath sounds, and feel for the person’s breath on your cheek and ear. Gasping is not considered to be normal breathing.

If the person isn’t breathing normally and you are trained in CPR, begin mouth-to-mouth breathing. If you believe the person is unconscious from a heart attack and you haven’t been trained in emergency procedures, skip mouth-to-mouth rescue breathing and proceed directly to chest compression.

BREATHING: Breathe for the person

Rescue breathing can be mouth-to-mouth breathing or mouth-to-nose breathing if the mouth is seriously injured or can’t be opened.

With the airway open (using the head-tilt, chin-lift maneuver) pinch the nostrils shut for mouth-to-mouth breathing and cover the person’s mouth with yours, making a seal.

Prepare to give two rescue breaths. Give the first rescue breath — lasting one second — and watch to see if the chest rises. If it does rise, give the second breath. If the chest doesn’t rise, repeat the head-tilt, chin-lift maneuver and then give the second breath. Begin chest compressions to restore circulation.

CIRCULATION: Restore blood circulation with chest compressions

Place the heel of one hand over the center of the person’s chest, between the nipples. Place your other hand on top of the first hand. Keep your elbows straight and position your shoulders directly above your hands.

Use your upper body weight (not just your arms) as you push straight down on (compress) the chest 2 inches (approximately 5 centimeters) . Push hard and push fast — give two compressions per second, or about 120 compressions per minute.

After 30 compressions, tilt the head back and lift the chin up to open the airway. Prepare to give two rescue breaths. Pinch the nose shut and breathe into the mouth for one second. If the chest rises, give a second rescue breath. If the chest doesn’t rise, repeat the head-tilt, chin-lift maneuver and then give the second rescue breath. That’s one cycle. If someone else is available, ask that person to give two breaths after you do 30 compressions.

If the person has not begun moving after five cycles (about two minutes) and an automatic external defibrillator (AED) is available, apply it and follow the prompts.

The American Heart Association recommends administering one shock, then resuming CPR — starting with chest compressions — for two more minutes before administering a second shock.

If you’re not trained to use an AED, a 911 operator may be able to guide you in its use. Trained staff at many public places are also able to provide and use an AED.

Continue CPR until there are signs of movement or until emergency medical personnel take over.